JP2009173550A - Method for producing hydrogenolysis product of polyhydric alcohol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a hydrogenolysis product from a polyhydric alcohol efficiently. <P>SOLUTION: This batchwise method for producing the hydrogenolysis product of the polyhydric alcohol is provided by performing the hydrogenolysis reaction, while removing water in a reaction liquid phase. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for efficiently converting a polyhydric alcohol and producing a hydrocracked product thereof with high selectivity.

It is important from the viewpoint of effective utilization of substances to convert polyhydric alcohols obtained from nature to other compounds by hydrocracking using a catalyst.
On the other hand, glycerin, which is used as a polyhydric alcohol in foods and medicine, has been increasing in production year by year. The reasons for this include the fear of supplying fossil fuels and the widespread use of biodiesel fuel, which has been growing against the background of global warming. Biodiesel fuel produced from plant raw materials produces glycerin during the production process. However, since the use of glycerin is limited at present, the supply is becoming excessive and its effective use is required. As one of them, conversion to C3 alcohols using a catalytic reaction has attracted attention worldwide.

C3 alcohols are useful as various industrial raw materials. Among the C3 alcohols, diols include 1,3-propanediol and 1,2-propanediol, and 1,3-propanediol is attracting attention as a polyester and polyurethane raw material.
In addition, 1,2-propanediol (hereinafter sometimes referred to as “1,2-PD”) is used in, for example, polyester resins, paints, alkyd resins, various plasticizers, antifreeze liquids, brake oils, and the like. It is useful for humectants, fruit juice viscosity enhancers, cellophane softeners for foods, cosmetics, pharmaceuticals, and the like.

As an effective use of glycerin, various methods for producing 1,2-PD by hydrogenolysis of glycerin have been proposed.
For example, as a catalyst, (1) a method using nickel-rhenium / carbon (for example, refer to Patent Document 1), (2) a method using ruthenium / carbon (for example, refer to Patent Document 2), (3) copper-zinc / A method using alumina (for example, see Patent Document 3), (4) a method using copper-zinc oxide (for example, see Patent Document 4), and (5) a method using copper-chromium (for example, see Non-Patent Document 1). (6) A method using ruthenium (see, for example, Patent Document 5) is known.
However, in these methods, the conversion rate of glycerin is low or the selectivity of 1,2-PD is low, so that it is not satisfactory. Particularly under low pressure, which is advantageous industrially, it is difficult to achieve both high reactivity and high selectivity, which is not satisfactory. Non-Patent Document 1 and Patent Document 5 describe the effect of water, and it is described that the selectivity is greatly reduced unless water is added in advance.

International Publication No. 03/035582 Pamphlet European Patent Application No. 523014 European Patent Application No. 523015 German Patent Application Publication No. 4302464 Applied Catalysis A: General, 281, 225, (2005) Japanese Patent Application Publication No. 2007/283175

  The present invention has an object to improve the reactivity in a method for producing a hydrogenolysis product of a polyhydric alcohol using a batch catalyst, and particularly when glycerin is used as the polyhydric alcohol, the reactivity of glycerin is improved. It is an object to improve and efficiently convert to 1,2-propanediol.

The present inventors have found that the above problem can be solved by removing water remaining in the reaction liquid phase with the progress of the reaction as a method for producing a hydrocracked product of polyhydric alcohol. It was.
That is, the present invention
(1) A process for producing a hydrocracked product of a polyhydric alcohol in a batch system, in which a polyhydric alcohol is brought into contact with hydrogen in the presence of a hydrogenation catalyst, and the reaction is carried out while removing water in the reaction liquid phase;
I will provide a.

  According to the present invention, it is possible to efficiently produce a hydrocracked product from a polyhydric alcohol, and in particular, it is possible to provide a method for efficiently producing 1,2-PD from glycerin. Moreover, by using this production method, glycerol can be efficiently converted under low pressure, and 1,2-PD can be produced with good selectivity.

In the method for producing a hydrocracked product of a polyhydric alcohol of the present invention, the polyhydric alcohol and hydrogen are heated in the presence of a hydrocracking catalyst to hydrocrack the polyhydric alcohol.
As the polyhydric alcohol, a compound having 2 to 6 hydroxyl groups is preferable. Specific examples include aliphatic or alicyclic polyhydric alcohols having 2 to 6 hydroxyl groups and 2 to 60 carbon atoms. Specifically, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, various propanediols, various dipropanediols, various tripropanediols, various butanediols, various dibutanediols, various pentanediols, various pentanetriols, various hexanediols, Examples include various hexanetriols, glycerin, diglycerin, triglycerin, various cyclohexanediols, various cyclohexanetriols, pentaerythritol, trimethylolpropane, and sugar alcohols such as sorbitol and mannitol. Among these, glycerin and sugar alcohols such as sorbitol and mannitol are preferable from an industrial viewpoint, and glycerin is particularly preferable.
The hydrocracked product of polyhydric alcohol in the present invention is obtained by causing hydrogen to act on polyhydric alcohol to decompose hydroxyl groups, and decomposes it to the extent that at least one hydroxyl group remains. The compound obtained is shown. For example, hydrogenolysis products of glycerin (number of hydroxyl groups in the molecule: 3) are C3 diol (hydroxyl groups in the molecule: 2) and C3 monool (number of hydroxyl groups in the molecule: 1).

As the hydrocracking catalyst, for example, at least one metal species selected from copper, nickel, cobalt, ruthenium, palladium, platinum, rhodium, etc., and a complex catalyst containing these metal atoms can be used. A solid catalyst in which a metal species is supported on a carrier such as alumina, silica, titanium oxide or the like can also be used. Among them, copper-containing catalysts (sometimes referred to as “copper catalysts”) are preferable, and copper-iron-aluminum, copper / silica, copper-zinc / titanium oxide, and copper Raney catalysts are particularly preferable. Among these, copper-iron-aluminum and copper / silica are preferable, and copper / silica is particularly preferable.
As the catalyst, a commercially available catalyst may be used. For example, a conventionally known method such as a precipitation method, an ion exchange method, an evaporation to dryness method, a spray drying method, a kneading method or the like is used on the carrier. It can be prepared by supporting a metal component.
The usage-amount of these catalysts is 0.01-20 mass parts with respect to 100 mass parts of polyhydric alcohols which are raw materials, Preferably it is 0.1-10 mass parts, More preferably, it is 0.3-6 mass parts.

In the method for producing a hydrolyzate of a polyhydric alcohol of the present invention, as a method for removing water in the reaction liquid phase, a method for inducing water into the gas phase as water vapor, or a dehydrating agent is present in the reaction vessel in advance. In addition, a method of absorbing liquid phase moisture can be used. In the method of inducing water as water vapor into the gas phase, gas can be circulated and promoted by inducing out of the reaction vessel. In this case, one or more of inert gases such as hydrogen, nitrogen, and argon are used. Can be used. In this invention, it is preferable to promote by circulating gas, and since hydrogen gas is used as a reaction reagent, hydrogen gas is preferable.
The removal of water does not have to be continuous, and the reaction efficiency is improved by removing a part of the water from the reaction system. The reaction efficiency here mainly refers to the reaction rate, and in the case of glycerin, it also means the conversion rate to 1,2-propanediol. In hydrocracking, water is produced from polyhydric alcohols. In a batch reaction system, water is accumulated in the system, so that the amount of water increases as the reaction proceeds. On the other hand, polyhydric alcohol decreases. The total amount of water finally produced varies depending on the polyhydric alcohol, but can be determined from the amount of polyhydric alcohol used in the reaction. In the present invention, the condition for removing water is any time from when the polyhydric alcohol in the reaction liquid phase has reacted 60 mol%, in other words, from the time when the amount of residual polyhydric alcohol has reached 40 mol% to the end of the reaction. When the total water content generated from the polyhydric alcohol is 1, the ratio (hereinafter sometimes referred to as “moisture ratio”) is 0.5 or less, preferably 0.4 or less, particularly preferably 0.8. It is preferable to remove water in the reaction liquid phase so as to be 3 or less. The amount of water in the reaction system should be small, and it is preferable to continuously expel water from the reaction system. In order to remove the water from the beginning of the reaction, it is preferable to remove the water from the reaction liquid phase by a method of circulating the gas described above. In terms of numerical values, after the time when 60 mol% of the polyhydric alcohol in the reaction liquid phase has reacted, the proportion of water in the reaction liquid phase is 0.5 or less, where 1 is the total water content generated from the polyhydric alcohol, It is preferable to keep it at 0.4 or less, particularly 0.3 or less.
In particular, in the conversion of glycerin to 1,2-propanediol, the smaller the amount of water in the liquid phase, the better the reactivity of glycerin. The amount of water can be calculated by extracting a sample over time and performing Karl Fischer analysis.

There are no particular restrictions on the reaction conditions, and the reaction conditions are appropriately selected according to the type of polyhydric alcohol and catalyst used. The hydrogen pressure is usually preferably 30 MPa or less at normal temperature, preferably 0.1 to 10 MPa, more preferably 0.5 to 5 MPa, and further preferably 0.5 to 3 MPa, from the viewpoint of industrialization. The reaction temperature can usually be hydrocracked at 80 ° C. or higher, but is preferably in the range of 130 ° C. to 350 ° C. from the viewpoint of the conversion rate of the polyhydric alcohol by hydrogenolysis and the selectivity of the decomposition products. The range of 160 to 300 ° C is more preferable, and the range of 180 to 250 ° C is particularly preferable.
As a reaction apparatus for the hydrocracking reaction, a batch system using a pressurizable apparatus such as an autoclave is preferable.

  In the method for producing a polyhydric alcohol hydrolyzate of the present invention, glycerin is preferably used as the polyhydric alcohol. By using this glycerin, 1,2-PD can be efficiently produced as a hydrocracked product.

Example 1
(Preparation of copper-iron-aluminum catalyst)
The following operation was performed to produce a copper-iron-aluminum catalyst having a copper / iron / aluminum atomic ratio of 1 / 0.8 / 1.8.
A reactor having a reflux condenser was charged with water (300 g), CuSO ₄ .5H ₂ O (48 g), FeSO ₄ .7H ₂ O (46.8 g) and aluminum hydroxide (12.8 g) while stirring. The temperature was raised to 96 ° C. The temperature was maintained at 95 ± 2 ° C. for 1 hour. Next, while maintaining this temperature, a solution of Na ₂ CO ₃ (44.8 g) dissolved in water (150 g) was added dropwise over about 80 minutes. A solution in which CuSO ₄ .5H ₂ O (4.8 g) and Al ₂ (SO ₄ ) ₃ .16H ₂ O (46.8 g) are dissolved in water (109.2 g) while maintaining the temperature at 95 ± 2 ° C. And a solution of Na ₂ CO ₃ (27.6 g) dissolved in water (98.2 g) were added dropwise at the same time. The aqueous solution of the metal salt was added dropwise over 60 minutes, and the aqueous solution of the alkaline substance was added dropwise over 30 minutes. A solution prepared by dissolving Al ₂ (SO ₄ ) ₃ .16H ₂ O (23.4 g) in water (53.5 g) was added dropwise thereto over 30 minutes. Then, a solution of Na ₂ CO ₃ (14.3 g) dissolved in water (54.9 g) was added dropwise over 30 minutes. Further, 10% NaOH aqueous solution was added dropwise to adjust the pH to 10.5. Aging was performed for 1 hour while maintaining the pH at 10.5. After completion of aging, the reaction product was filtered with suction. The precipitate was washed 3 times with 450 ml of water each time and then dried at 100 ° C. The dried product was lightly pulverized and calcined in the air at 750 ° C. for 1 hour to obtain a copper-iron-aluminum catalyst using alumina as a carrier.

(Hydrocracking)
To a 500 mL iron autoclave with a stirrer, 10 g of the copper-iron-aluminum catalyst obtained by the above method and 200 g of glycerin were added, and hydrogen substitution was performed. Thereafter, hydrogen was introduced into the liquid, and the pressure in the autoclave was maintained at 2 MPa, and 5 L / min. The mixture was heated and allowed to react at 230 ° C. while flowing at 25 ° C. and H ₂ . Moisture in the liquid phase was discharged out of the reaction vessel as water vapor from a discharge port provided at the top of the iron autoclave by hydrogen introduced into the liquid.
After the reaction time sample and the reaction end solution were filtered, the water content was measured by Karl Fischer analysis and analyzed by gas chromatography under the following conditions to quantify the product. From these values, residual glycerin (mol%) and The ratio of moisture when the total moisture generated from glycerin in the liquid phase was 1 was determined. Further, a first-order reaction rate constant k was calculated from the amount of residual glycerin measured over time, and this was used as a measure of the reaction rate. These results are shown in Table 1.

〔Gas chromatography〕
Column: Ultra-alloy capillary column 15.0 m × 250 μm × 0.15 μm (manufactured by Frontier Laboratories), detector: FID, injection temperature: 300 ° C., detector temperature: 350 ° C., He flow rate: 4.6 mL / min.

Examples 2 and 3
Using the catalyst obtained in Example 1, hydrocracking reaction was carried out under the conditions described in Tables 1 and 6. That is, in Example 2, the flow rate under the hydrogen flow condition was 5 L / min. To 1 L / min. In Example 3, the hydrogen circulation method was introduced into the gas phase part above the reaction solution, not in the liquid, and the water vapor in the gas phase was guided out of the reaction vessel, so that the water vapor was removed from the liquid phase. It was made to supply to a phase and the water | moisture content in a liquid phase was removed indirectly. The results are shown in Table 1.

Example 4
(Copper Raney catalyst)
The reaction was carried out in the same manner as in Example 1 except that a copper Raney catalyst (product number RC-300) manufactured by Nikko Rica was used.

Example 5
(Preparation of copper-zinc / titanium oxide catalyst)
The reactor was charged with copper nitrate (100 g) and zinc nitrate (30 g), dissolved in water (2000 g), and then heated with stirring. Titanium oxide (33 g) was charged at 50 ° C., 10% by weight Na ₂ CO ₃ aqueous solution (546 g) (metal salt and equimolar Na ₂ CO ₃ ) was added dropwise at 90 ° C. over 1 hour, and after aging for 1 hour, The precipitate was filtered and washed with water, dried at 110 ° C. for 10 hours, and calcined at 600 ° C. for 1 hour. The obtained metal oxide had a copper / zinc atomic ratio of 4/1 and a supported amount with respect to titanium oxide as a support was 50% by mass. Using this titanium oxide-supported copper oxide-zinc oxide as a catalyst, a hydrogenolysis reaction was carried out in the same manner as in Example 1.
The results of Example 4 and Example 5 are shown in Table 2.

Examples 6-11
(Copper / Silica catalyst)
A hydrocracking reaction was carried out under the conditions shown in Tables 3 and 4 using a pulverized product of a copper / silica catalyst (product number F01B) manufactured by JGC Chemical Co., Ltd. having an atomic ratio of Cu / Si of 1 / 0.55. . Examples 6-9 change the usage-amount of a copper / silica catalyst with 5, 2, 1, 0.5 mass part with respect to 100 mass parts of glycerol, and Examples 6, 10, and 11 change reaction temperature. The reaction was carried out at 230, 220 and 200 ° C., and the influence of these factors was confirmed. The results are shown in Tables 3 and 4.

Comparative Examples 1-6
In a 500 mL iron autoclave with a stirrer, 200 g of raw material glycerin and a pulverized product of a copper / silica catalyst (product number F01B) manufactured by JGC Chemical Co., Ltd. were added in an amount of 5 parts by mass with respect to 100 parts by mass of glycerin, followed by hydrogen substitution. As shown in Table 5 and Table 6, after introducing hydrogen up to 1 MPa at room temperature and heating to the reaction temperature described in the table, the hydrogen pressure was 6 MPa in Comparative Examples 1-3, 2 MPa in Comparative Example 4, In Comparative Examples 5 and 6, the pressure was increased to 15 MPa, and after that, the hydrogen pressure was maintained in a sealed state without flowing hydrogen, and the reduced pressure was maintained by replenishing hydrogen to perform a hydrogenolysis reaction. In Comparative Example 2, the reaction was carried out using a solution in which the molar ratio of water to glycerol as a raw material was 1 / 1.3, and in Comparative Examples 3 and 6, 100 / 20.5.

  Compared to Examples 1, 4, 5, and 6 in which the types of catalysts used under the same conditions were different, the reaction was carried out without passing hydrogen on the basis of Example 6 using the most active copper / silica catalyst. Compared to Comparative Example 1 in which the reaction was carried out without removing the water in the liquid phase, similarly, the reaction temperature was 230 ° C. and the amount of catalyst used was 5 parts by mass with respect to 100 parts by mass of glycerin. In Examples 1 to 6, the glycerin reactivity was improved from the time required until the completion of the reaction or the amount of residual glycerin at the 8th hour of the reaction, and the reaction rate was improved particularly in the later stage of the reaction. To do. In addition, Examples 1-6 also had good selectivity for 1,2-PD. Moreover, when Example 6 and Comparative Example 1 are compared, the selectivity of Example 6 is improved. From the results of Table 3, Table 4 and Table 5, in Examples 7 to 8 in which the amount of copper / silica catalyst used is small and in Examples 10 and 11 in which the reaction temperature is low, the reactivity of glycerin is higher than that in Comparative Example 1. In particular, the reaction rate is fast in the late reaction stage. In addition, the selectivity of 1,2-PD was also good. In Example 9, in which the amount of catalyst used was 1/10 compared to Comparative Example 1, the reaction rate was high in the late reaction period, and the selectivity for 1,2-PD was also good. From the results of Tables 3 and 5, comparing Example 10 and Comparative Example 4 in which the reaction temperature and the amount of catalyst used are the same, it is clear that the time required for Example 10 in which moisture was removed to complete the reaction was clear. Shorter and improved selectivity.

Examples 12 and 13
Example 12 in which a copper-iron-aluminum-based catalyst was used and the hydrogen pressure in the system was 15 MPa, similarly, the hydrogen pressure was 15 MPa, and a copper / silica catalyst (product number F01B) manufactured by JGC Chemical Co., Ltd. was ground. In Example 13 using the product, the hydrogenolysis reaction of glycerin was performed in the same manner as described above.
As shown in Table 6, as compared with Comparative Example 5, Examples 12 and 13 reacted while removing the retained water in the reaction liquid phase had improved glycerin reactivity. The speed is fast. In addition, Examples 12 and 13 had good selectivity for 1,2-PD.

Example 14
To a 500 mL iron autoclave equipped with a stirrer, 10 g of a pulverized product of a copper / silica catalyst (product number F01B) manufactured by JGC Chemical Co., Ltd. and 200 g of glycerin were added and hydrogen-substituted. Furthermore, after introducing hydrogen up to 1 MPa at room temperature and heating to 230 ° C., the hydrogen pressure is increased to 15 MPa, and the reduced pressure is maintained by replenishing hydrogen in a sealed state. The decomposition reaction was carried out for 2 hours. At this time point, 85.5 mol% of the added glycerin reacted, and the ratio of water in the reaction solution was 0.93 when the total water content generated from glycerin was 1.
Thereafter, the iron autoclave was cooled to 150 ° C., and hydrogen was introduced into the liquid while maintaining the pressure in the autoclave at 1.5 MPa, and 10 L / min. (25 ° C., 0.1 MPa) was passed for 2 hours to remove moisture. Then stop the flow of hydrogen, heat up to 230 ° C, raise the hydrogen pressure to 15 MPa, and then keep the pressure in a sealed state without flowing hydrogen, replenishing the reduced pressure with hydrogen. However, the hydrocracking reaction was performed again. The results are shown in Table 7.
Compared with Comparative Example 5, in Example 14 in which water was removed during the reaction, the reactivity of glycerin was improved after water removal, and the selectivity of 1,2-PD was also good.

  According to the present invention, the hydrogenolysis product from polyhydric alcohol, particularly glycerin, is obtained by contacting polyhydric alcohol with hydrogen in the presence of a hydrogenation catalyst and removing water in the reaction liquid phase. An efficient method for producing 1,2-PD from In particular, by using this production method, glycerin can be efficiently converted and 1,2-PD can be produced with good selectivity under a low pressure industrially advantageous.

Claims (5)

  A process for producing a hydrolyzate of a polyhydric alcohol in a batch system, wherein the polyhydric alcohol is brought into contact with hydrogen in the presence of a hydrogenation catalyst and the reaction is carried out while removing water in the reaction liquid phase.   At any point in time from when 60 mol% of the polyhydric alcohol in the reaction liquid phase has reacted until the end of the reaction, the water content in the reaction liquid phase is 0.5 or less, assuming the total water content generated from the polyhydric alcohol as 1. The method for producing a hydrocracked product of a polyhydric alcohol according to claim 1, wherein water in the reaction liquid phase is removed so that the ratio is as follows.   The method for producing a hydrocracked product of a polyhydric alcohol according to claim 1 or 2, wherein the hydrogenation catalyst is a copper-containing catalyst.   The manufacturing method of the hydrogenolysis product of the polyhydric alcohol in any one of Claims 1-3 whose polyhydric alcohol is glycerol.   The method for producing a hydrocracked product of a polyhydric alcohol according to claim 4, wherein the hydrocracked product is 1,2-propanediol.